Buoyancy device



FIG. 1 is a front perspective view of a buoyancy device having left-right, top-bottom, and front-rear symmetry;

FIG. 2 is a front elevation view of the buoyancy device of FIG. 1; and

FIG. 3 is a right side perspective view of the buoyancy device of FIG. 1; and,

FIG. 4 is a top plan view of the buoyancy device of FIG. 1. 

CLAIM The ornamental design for a buoyancy device, as shown and described. 